Aww anak, yan talaga ang challenging part ng blended families e. Kausapin mo sya ng maayos na solo time, then explain na hindi lahat ng friendships stay the same, lalo na when new people enter the group, hindi yan dahil sa kanya or sa step brother, ganyan lang talaga ang dynamics ng barkada sometimes. A few of us mums with step-siblings noticed na ang best approach is to validate his feelings first (like "alam ko nakakasad yan"), then encourage him to find his own interests or activities din, joining clubs, sports, anything na para truly sa kanya, kaya may confidence sya na hindi dependent sa isang friend group lang. Ang mahalaga siguro is na ipakita mo he's still loved at valued at home, dahil yan ang foundation niya. But honestly po, if it's really affecting his confidence or mood na malaki, might be worth chatting with his guidance counselor or a child psychologist din, they have better tools to help him navigate yan. Rooting for your son!